Sandal upper



FIG. 1 is a perspective view of a sandal upper showing my new design;

FIG. 2 is a left side view thereof;

FIG. 3 is a right side view there;

FIG. 4 is a front view thereof;

FIG. 5 is a rear view thereof; and,

FIG. 6 is a top view thereof.

Environmental features shown in broken lines are for illustrative purposes only and form no part of the claimed design. 

CLAIM The ornamental design for a sandal upper, as shown and described. 